Evaluation of early apoptosis marker and DNA fragmentation in spermatozoa of infertile men with varicocele

Background: The most common reason of infertility due to male factors is varicocele. Varicocele is defined as a palpable elongated, dilated and tortuous testicular pampiniform plexus of veins in the spermatic cord. Although it is not clear that how exactly varicocele causes infertility, spermatogenesis defect because of disruption of testicular thermoregulation and increase in reactive oxygen species (ROS) is proposed to be the main explanation. It is shown that heat stress and oxidative stress can initiate programmed cell death known as apoptosis. Therefore, the aim of this study was to compare sperm apoptotic markers (externalization of phosphatidylserine (EPS) and DNA fragmentation) between infertile men with varicocele and fertile individuals.Methods: Sperm concentration, motility and morphology were assessed according to World Health Organization (WHO) 2010 guidelines in semen samples of 10 infertile men with varicocele and 10 fertile individuals. Sperm EPS and DNA fragmentation were assessed using Annexin V kit and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) stained by flow cytometry and florescent microscopy techniques, respectively. For data analysis, independent T- test statistics analysis was performed between two groups.Result: No significant difference was observed in level of EPS between two groups. However, sperm concentration, motility, and percentage of spermatozoa with normal morphology were significantly lower, while percentage of sperm with fragmented DNA was significantly higher in infertile men with varicocele compared to fertile individuals.Conclusion: Apoptosis is active in testis of men with varicocele and this phenomenon can disturb spermatogenesis process. Therefore, it may be concluded that the observed decreased sperm parameters is due to activity of apoptosis.

Keywords:

Apoptosis , DNA fragmentation , Externalization of phosphatidylserine , Sperm parameters , Varicocele